ddcui Overview

ddcui is a graphical user user interface for ddcutil, implemented using Qt. It is considered beta level code. Many features are not yet fully implemented, including online help, error reporting, and proper interpretation of certain peculiar VCP features codes.

This page collects the beginnings of ddcui documentation, which is incomplete but growing.

Source code and prebuilt packages:

Command line options of interest to general users:

Option Comments
--sleep-multiplier=number Sleep adjustment factor, can include decimal point, e.g. .1, 10
--ddc Report DDC protocol and data errors to terminal
--nousb Skip detection of monitors using USB for MCCS
--styles List available Qt styles
--style=style-name Use the specified Qt style


Unexpected Behavior

It is possible for feature values reported in ddcui to become out of sync with actual monitor values. - If feature values are changed using the monitor's On Screen Display. - If feature values are changed by another program, including the command line program ddcutil. - Some monitors will change their state (e.g. red gain) when the value in the GUI changes. However, the monitor still reports the old value, which is shown in ddcui. This is a bug in the monitor's DDC/CI implementation. - Conversely, some monitors will report a newly set value, but the observed state of the monitor is unchanged. Again, this is a bug in the monitor's DDC/CI implementation.

In some, but not all, cases, ddcui can be resynced with the actual monitor settings using menu item Actions->Rescan Monitor Values.

User Interface Options

  • When swiping the mouse or using the mouse wheel to scroll the VCP Features section, it is
    possible to accidentally move a slider that changes a continuous feature value. Optionally, the UI behavior can be altered to require that the control key be held down in order to move a slider. This behavior is modified using dialog Options->User Interface Options->Require control key to move sliders.

For basic instructions on building ddcui, see file BUILDING.md. Both a CMake CMakeLists.txt and a Qt ddcui.pro file are provided.

Pages with additional ddcui information: :
- Building ddcui
- Prebuilt Packages